Remove unnecessary newline at the end of the webapiaot csproj

[sander1095]

Remove unnecessary newline at the end of the webapiaot csproj

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This PR removes a lingering newline at the end of the webapiaot csproj

Description

In #60337 I added OpenAPI support to the dotnet new webapiaot template. This adds the Microsoft.AspNetCore.OpenApi package by default.

I just tested this locally by installing the preview4 build. I saw that the .csproj has an extra newline at the end, before the </project> tag. The dotnet new webapi template doesn't have this, which means this is a bit inconsistent

I removed this extra newline in this PR to ensure both templates behave the same way.

Fixes #59564

[dotnet-policy-service]

Thanks for your PR, @@sander1095. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[sander1095]

Hi @captainsafia ! Perhaps you can have a quick peek at this 1LOC PR change :)